Description of a new genus and species of Candonopsini (Crustacea, Ostracoda, Candoninae) from the alluvial valley of the Upper Paraná River (Brazil, South America)

Abstract. The genus Candobrasilopsis gen. nov. is here described, with C. rochai gen. nov. sp. nov. as type species, from the alluvial valley of the Upper Paraná River. The enigmatic Candonopsis brasiliensis Sars, 1901 is here redescribed and transferred to this new genus, the new combination being Candobrasilopsis brasiliensis (Sars, 1901). The new candonid genus belongs to the tribe Candonopsini, because of the absence of the proximal seta on the caudal ramus. It is closely related to Latinopsis Karanovic & Datry, 2009, because of the relatively short terminal segment of the mandibular palp (length less than 1.5 times the basal width, while this segment is longer than three times the basal width in Candonopsis) and the large and stout b-seta on the T1. However, it differs markedly from Latinopsis in the size and shape of the calcifi ed inner lamellae of both valves and in the type of hemipenis. We also discuss the doubtful allocation of several other genera to the Candonopsini, raise Abcandonopsis Karanovic, 2004 to generic status and reassess the uncertain position of Candonopsis anisitsi Daday, 1905 within Latinopsis.


Introduction
There are approximately 2000 described species and ca.200 described genera of Recent, free-living, non-marine ostracods in the world (Martens et al. 2008;Martens & Savatenalinton 2011).About 1000 species and 100 genera of these belong to the family Cyprididae Baird, 1845, and ca.500 species to the family Candonidae Kaufmann, 1900.The latter family was thought to be the most speciose in the northern hemisphere and to be of relatively recent origin (Danielopol 1978), but several recent papers document the presence of (sometimes speciose) lineages in the (sub-)tropics and in the southern hemisphere (Broodbakker 1983;Martens 1992, and several papers on Australian candonids summarised

Study area
The alluvial valley formed by the Upper Paraná River incorporates various fl uvial systems; each of these has a variety of environment types, ranging from the river itself, over connecting channels linking with open lakes and, fi nally, closed lakes.The Upper Paraná River consists of a large braided channel, with an extensive fl oodplain (maximum width of 20 km) and high sediment accumulation in its bed, creating sand bars and islands of diverse sizes (from some hundreds of meters to several kilometers in length) (Agostinho & Zalewski 1996;Agostinho et al. 2004).The alluvial valley of the Upper Paraná River, apart from the main channel of the Paraná River, also includes the Ivinhema and Baía Rivers, and associated with it, the isolated lakes of the Taquaruçu area (Souza Filho & Stevaux 2004) (Figure 1).

Material
The material for the present paper was collected in March, July and November of 2004 and in February of 2011, in the alluvial valley of the Upper Paraná River.Ostracods were sampled using a rectangular net (28 cm x 14 cm, mesh size ca.160 μm) hauled close to the sediment-water interface for littoral collections.Floating vegetation (Eichhornia crassipes, Pistia stratiotes, Hydrocotyle rannunculoides and Salvinia spp.) was hand-collected, and roots were thoroughly washed in a bucket.The residues were washed in the same hand net.
All specimens with OC numbers are stored in the Ostracod Collection of the Royal Belgian Institute of Natural Sciences, Brussels (Belgium).The material with MZUSP numbers is stored in the Museu de Zoologia da Universidade de São Paulo, São Paulo (Brazil).

Morphological analyses
Ostracods were dissected with valves stored dry in micropalaeontological slides and soft part in glycerine in sealed slides.Drawings of soft parts were made with camera lucida with a compound microscope (WILD HEERBRUGG).Valves were illustrated and measured using scanning electron microscopy (Philips XL30 SEM at RBINS, Brussels).Fig. 1.Map of the area, indicating localities of Candobrasilopsis rochai gen.nov.sp.nov.and C. brasiliensis (Sars, 1901) (Sars, 1901)  ), DO = dissolved oxygen (mg L -1 ).Chaetotaxy of the limbs follows the model proposed by Broodbakker & Danielopol (1982), revised for the A2 by Martens (1987) and for the T3 by Meisch (2000).Higher taxonomy of the Ostracoda follows the synopsis by Horne et al. (2002).

Diagnosis
Anterior calcifi ed inner lamella broad, anterior inner margin sinuous, posterior calcifi ed inner lamella narrow, posterior inner margin running parallel to valve margin.Terminal Md-palp segment short (L ≤ 1.5 x basal width).Prehensile palps one-segmented, base infl ated, distal fi nger long, hook-like.Hemipenis of triangular type, without protruding lobes a and b.Caudal ramus without proximal seta, distal seta reduced to a small spine.

Etymology
Named after the country of Brazil (Brasil in Portuguese), with "Cando-" and "-opsis" denoting relationship to Candonopsis.

Differential diagnosis
This new genus is closely related to Candonopsis Vavra, 1891 (with type species C. kingsleyi (Brady & Norman, 1870)) and to Latinopsis Karanovic & Datry, 2009 (type species L. patagonica Karanovic & Datry, 2009).It differs from Candonopsis s.s.mainly in the presence of a short terminal Md-palp segment, by the fact that the prehensile palps have 2 distal setae (1 in Candonopsis) and by the relatively simple attachment of the caudal ramus (1 lateral branch in Latinopsis and in Candobrasilopsis gen.nov., 3 in Candonopsis s.s.).
The new genus differs from Latinopsis (only L. patagonica) mainly in the presence of a broad anterior calcifi ed inner lamella with sinuous inner margin (narrow and with evenly rounded inner margin in Latinopsis) and by the absence of protruding lobes 'a' and 'b' in the hemipenis (present in Latinopsis).

Remarks
We propose to tentatively transfer C. anisitsi Daday, 1905 to Candobrasilopsis gen.nov.based on the morphology of the hemipenis and the prehensile palps (see discussion below).

Diagnosis
A species of the tribe Candonini, with elongated valves, greatest height well behind the middle; carapace in lateral view with weakly rounded dorsal margin, not straight.Anterior calcifi ed inner lamella in both valves broad; almost 1/4 of total length and with inner margin sinuous, not parallel to valve margin.Base of right prehensile palp broad, almost triangular, distal part curved, distal tip slightly expanded, set with two subequal lateral setae.Left prehensile palp larger and more elongated, with hook-like distal part, distal tip slightly swollen.Hemipenis with triangular ls, distinctly pointed, proximo-dorsal expansion small, ms rounded and without ventral, wart-like expansion.

Etymology
The new species is named after Prof Dr Carlos Eduardo Falavigna da Rocha (USP, São Paulo, Brazil), in recognition of his vast contributions to the taxonomy of Brazilian Copepoda, but also in acknowledgement of his initiative to start research on terrestrial Ostracoda in South America.

Type material
All type material was collected on 10 Nov. 2004 by the authors, by washing roots of Eichhornia crassipes (PAR 195) and Pistia stratiotes (PAR 193) over a hand net with mesh size 160 μm.See Table 1 for measurements of water chemistry at time of collecting.

Other material investigated
See Table 1 for a list of localities where the present species was collected.Specimens MZUSP.28113,MZUSP.28114,MZUSP.28115(♂♂) and MZUSP.28116(♀) are here used for illustrations and are also deposited in the Museu de Zoologia da Universidade de São Paulo, São Paulo (Brazil).Illustrated specimens are listed in Table 2.

Differential diagnosis
The new species differs from the congeneric species (C.brasiliensis), and indeed from all other Candonopsini, by the shape of the valves, by the peculiar shape of the prehensile palp (with distal part swollen in Rpp) and by the size and shape of the hemipenis.

Description of male
Valves (Fig. 2A, B) elongated, with greatest height situated behind the middle (and bluntly pointed there) anteriorly rather narrowly and posteriorly rather broadly rounded, RV and LV of highly similar shape; anterior calcifi ed inner lamella broadly rounded, posterior calcifi ed inner lamella very narrow and almost disappearing towards the dorsal side; inner margin of anterior calcifi ed inner lamella slightly sinuous in both valves.
Carapace in right lateral view (Fig. 2C) showing LV overlapping RV slightly on all sides; external surface of valves smooth.In dorsal view (Fig. 2D), carapace lancet-shaped, sharply pointed in the anteriorly, more broadly so posteriorly, greatest width situated well behind the middle.
Carapace also in ventral view (Fig. 2E, F) lancet-shaped, with anterior side more acutely pointed than posterior side.A1 (Fig. 3A) with 5 terminal segments relatively elongated (L = at least 1.5 x basal width).Basal part of A1 (= undivided protopodite) with 2 long sub-apical, ventral setae and two shorter setae on the dorsal side, one at ca. mid-length, the other sub-apical.Next (second) segment with one long (reaching beyond basis of penultimate segment) dorso-apical seta, no ventro-apical seta present.Third segment with one small sub-apical seta on both ventral and dorsal sides.Fourth and fi fth segments with two longer dorsoapical and 1 shorter ventro-apical setae.Sixth segment with three longer dorso-apical and one shorter ventro-apical setae.Seventh (terminal segment) most elongate of all, slightly sinuous, bearing one short and two longer setae and one aesthetasc Ya, the latter shorter than the shorter seta.A2 (Fig. 3B) with basal segment very broad, wide and relatively long, basally with 2 unequal setae, one relatively long and slender, the other very short and broad, both hirsute; apically with a ventral seta.Remnant of exopod consisting of a short plate, one long and two very short setae.Endopod consisting of 4 segments (penultimate segment divided).First endopodal segment long, carrying one long aesthetasc Y on the ventro-basal side, and one long and one short ventro-apical setae.Second endopodal segment shorter and smaller, but still rectangular with one ventral aesthetasc y1 inserted about mid length, 3 t-setae, with t1 a long, hirsute setae, t2 and t3 modifi ed in the male-bristles.Dorso-apically with 3 short setae of unequal length.Third endopodal segment with apical chaetotaxy sexually dimorphic, with z1 and z3 being short setae, z2 being modifi ed into a long claw; G2 a long claw, G1 a long seta and G3 a short setae, aesthetasc y2 short and ventro-apically inserted.Terminal (4 th ) segment small, distally with claws GM (long) and Gm (short), aesthetasc y3 with its companion seta, fused at the basis and of c equal length, and seta g, slightly longer than y3.
Md with coxa (Fig. 3D) relatively elongated, distally set with a series of strong teeth.Md-palp (Fig. 3C) consisting of 4 segments.Basal segment dorsally carrying the respiratory plate (not shown), ventroapically with 2 long hirsute setae (s1 & s2) and the alpha seta, the latter proximally with a broad base and a fl agellum-like, distal part.Second segment dorso-apically with 2 seta of unequal length, ventro-basally with a short, stout and hirsute seta and ventro-apically with a group of 5 setae: 3 long and hirsute setae (similar to the two s-setae of the previous segment), a shorter, less hirsute seta and the short and hirsute beta-seta.Third segment with a group of 3 dorso-subapical setae, the latter smooth, a central group of two setae, one of which being the gamma seta and ventro-apical group of 4 unequal setae.Terminal segment rectangular, apically set with two large claws and an uncertain number of smaller setae.Mx1 (Fig. 3E) with a basal (basipodite) part carrying a large respiratory plate (exopodite), 3 endites and a two-segmented palp (endopodite).Respiratory plate elongated, carrying more than 20 respiratory rays, some quite short, others long (Fig. 3F).Palp with fi rst segment carrying 3+1 apical setae; terminal segment short and broad, carrying 2 longer claws and c 3 short setae.Chaetotaxy of three endites impossible to determine.Sideways directed bristles near fi rst endite long and stout.T1 (sometimes called Mx2 -Fig.4A) consisting of basal part (basipodite), carrying respiratory plates (not shown), a palp (modifi ed to prehensile palp in males) and an exopodite (?) distally set with 14-15 setae of different morphology and length.Basal plate set with one long and stout 'b'-seta, a shorter and more slender 'd'-seta and two 'a'-setae of unequal length.Prehensile palps (Fig. 4A, B) one-segmented, distally hook-like and set with two unequal, sub-apical setae; palps slightly asymmetrical, right prehensile palp (Fig. 4B) basally slightly more swollen and with distal hook like expansion apically swollen.T2 (walking limb -Fig.4C) with 4-segmented endopodite (penultimate segment divided) and elongated.First segment with long seta d1.Knee-segment devoid of seta d2.First segment of endopod especially elongated, with short ventro-apical seta.Second segment also with one short ventro-apical seta.Third segment with two ventro-apical seta, one short, one slightly longer.Terminal segment with one short apical and one short sub-apical seta and a long apical claw.T3 (cleaning limb -Fig.4D) as typical of the family.First segment with three long setae, one medial (d1), one subapical (d2) and one apical (dp).Second segment with one subapical seta (e).Third segment with one long subapical seta (f).Penultimate segment with one short and curved subapical seta (g).Terminal segment well-separated from penultimate segment and carrying three setae: one long and refl exed (h3) and two side-ways directed (h1 & h2), the latter subequal.
Caudal ramus (furca -Fig.4E) with stout ramus and two stout apical claws.Proximal setae missing, distal seta a small spine.Attachment to caudal ramus (Fig. 3G) long and stout, distally bifurcated and with additional lateral branch at c mid-length.Length ratio ramus/largest claw = 1.51.Hemipenis (Fig. 7A) relatively small, with rounded ms and bluntly pointed, triangular ls, the latter furthermore with small proximo-dorsal expansion; labyrinth short and stout, postlabyrinthal spermiductus narrow and straight, without additional coils, but with a weak bent at the most distal part.

Description of female
Valves (Fig. 2G, H) and Cp (Fig. 2I) in lateral view similar to those in the male, RV in inner view dorsally more rounded and less bluntly pointed than in the male.Cp in D and V views (Fig. 2J, K) equally narrow and lancet-shaped, in D view with slight rostrum, in ventral view without the pronounced (anterior and posterior) rostral keels, typical of the male.
Soft parts (Figs 5B-E, 6A-E) largely as in the male, but with sexually dimorphic A2 and T1.A2 (Fig. 5A) with setae t1-4 setae like, not transformed; z1 and z2 short and slender, seta z3 short and stout.Claws G1, G2, G3 and GM all reaching to about the same point.T1 (Fig. 6F) with basal part as in the male.Endopod a broad palp, with two short and one long distal setae.

Measurements
See Table 3.

Ecology
See below under C. brasiliensis.

Remarks
This species was originally identifi ed by us as Candonopsis annae (Mehes, 1914), but subsequent detailed analysis of the valves and soft parts showed that this was not so, and that the populations from the alluvial valley of the Upper Paraná River needed be described as a new species.Some specimens (Fig. 2F) give the impression that they have an anterior rostrum and a postero-ventral keel.This was observed in 2 male specimens, after their carapaces were dried for SEM.So either these 2 specimens belong to a different species, which is not very likely, or the weak calcifi cation of the valves (typical of Candonopsis-like species) has made those parts of the valve implode while drying in air.(Sars, 1901) (Sars, 1901) comb.nov.

Candobrasilopsis brasiliensis
part, distal tip not swollen.Hemipenis with triangular ls, bluntly pointed, bearing large and rounded proximo-dorsal expansion, and with rounded ms bearing a ventral, wart-like expansion.
Type material and type locality Sars (1901: 46) wrote: "Only 2 female specimens of this form were secured.They were found in one of my aquaria prepared with mud from São Paulo".No detailed locality information is provided.Given de expansion of the city of São Paulo over the past 100 years, the actual locality from which the mud was collected has meanwhile almost certainly been destroyed.(1901) based his description and illustration (only a dorsal and left lateral view of a carapace) on 2 female specimens only.As females in this genus do not have the most specifi c characters which are in the hemipenis and prehensile palps of the male, we have decided not to rely on the type material to redescribe this species.Rather, we use new material from the Upper Paraná River, about 700 km WNW from São Paulo City.

Material used for the present redescription
See Table 1

Differential diagnosis
This species differs from the congeneric species (C.rochai gen.nov.sp.nov.), by the shape of the valves, by rounded basal part of the right prehensile palp and by the large hemipenis with blunt tip and the ms with a ventral wart-like expansion.

Redescription of male
Valves (Fig. 8A, B) elongated, with greatest height situated well behind the middle (and bluntly pointed there), middle 2/3 of the dorsal margin straight and sloping towards the anterior margin; anterior margin rather narrowly and posterior rather broadly rounded.RV and LV of highly similar shape; anterior calcifi ed inner lamella broadly rounded, posterior calcifi ed inner lamella very narrow and almost disappearing towards the dorsal side; inner margin of anterior calcifi ed inner lamella slightly sinuous in both valves.
Carapace in right lateral view (Fig. 8C) showing LV overlapping RV slightly on postero-dorsal and ventral sides; external surface of valves smooth.
A1 (Fig. 9C) with 5 terminal segments relatively elongated (L = at least 1.5 x basal width).Basal segment of A1 (= undivided protopodite) with 2 long sub-apical, ventral setae and two shorter setae on the dorsal side, of the latter one inserted at c mid-length, the other sub-apical.Second segment of basal      part with one long (reaching beyond basis of fi fth segment) dorso-subapical seta, no ventro-apical seta present.Third segment with one small sub-apical dorsal and ventral setae.Fourth and fi fth segments with two longer dorso-apical and 1 shorter ventro-apical setae.Sixth segment with three longer dorsoapical and one shorter ventro-apical setae.Seventh (terminal segment) most elongate of all, slightly sinuous, bearing one short and two longer setae and one aesthetasc Ya, the latter shorter than the shorter seta.
A2 (Fig. 9A, B) with basal segment broad, wide and relatively long, basally with 2 unequal setae, one relatively long and slender, the other very short and broad, both hirsute; apically with a ventral seta.Remnant of exopod consisting of a short plate, one long and two very short setae.Endopod consisting of 4 segments (penultimate segment divided).First endopodal segment long, carrying one long aesthetasc Y on the ventro-basal side, and one long and one short ventro-apical setae.Second endopodal segment shorter and smaller, but still rectangular with one ventral aesthetasc y1 inserted about mid length, 3 t-setae, with t1 a long, hirsute setae, t2 and t3 modifi ed in the male-bristles; this segment dorsoapically with 3 short setae of unequal length.Third endopodal segment with apical chaetotaxy sexually dimorphic, with z1 and z3 being short setae, z2 being modifi ed into a long claw; G2 a long claw, G1 a long seta and G3 a short setae, aesthetasc y2 short and ventro-apically inserted.Terminal (4 th ) segment (Fig. 9B) small, distally with claws GM (long) and Gm (short), aesthetasc y3 with its companion seta, fused at the basis and with seta almost twice as long as aesthetasc, and seta g, clearly longer than y3.
Md with coxa (Fig. 9F) relatively elongated, distally set with a series of strong teeth.Md-palp (Fig. 9D) consisting of 4 segments.Basal segment dorsally carrying the respiratory plate (not shown), ventroapically with 2 long hirsute setae (s1 & s2) and the alpha seta, the latter proximally with a broad base and a fl agellum-like, distal part.Second segment dorso-apically with 2 setae of unequal length, ventrobasally with a short, stout and hirsute seta and ventro-apically with a group of 5 setae: 3 long and hirsute setae (similar to the two s-setae of the previous segment), a shorter, less hirsute seta and the short and hirsute beta-seta.Third segment with a group of 3 dorso-subapical setae, the latter smooth, a central apical group of two setae, one of which being the gamma seta and ventro-apical group of 4 unequal setae.Terminal segment rectangular, apically set with two large claws and an uncertain number of smaller setae.
T1 (sometimes called Mx2 -Fig.10A) consisting of basal part (basipodite), carrying respiratory plates (not shown), a palp (modifi ed to prehensile palp in males) and an exopodite (?) distally set with 14-15 setae of different morphology and length.Basal plate set with one long and stout 'd'-seta, a shorter and more slender 'b'-seta and two 'a'-setae of unequal length.Prehensile palps (Fig. 10D, E) onesegmented, distally hook-like and set with two unequal, sub-apical setae; palps slightly asymmetrical, Rpp (Fig. 10D) slightly smaller than Lpp, distal part of apical hook slightly swollen in Lpp, not at all in Rpp.
Third segment with two ventro-apical setae, one short, one slightly longer.Terminal segment with one short apical and one short sub-apical seta and a long apical claw.
Terminal segment well-separated from penultimate segment and carrying three setae: one long and refl exed (h3) and two side-ways directed (h1 & h2), the latter subequal.
Hemipenis (Fig. 7C) large, with medial shield rounded and with additional ventral protuberance, lateral shield bluntly pointed, triangular and with rounded, proximo-dorsal expansion; labyrinth short and stout, postlabyrinthal spermiductus narrow and straight, without additional coils, but with a weak bent at the most distal part.

Redescription of female
Valves (Fig. 8F, G) and Cp (Fig. 8H) in lateral view similar to those in the male; valves in inner view slightly more elongated and less high than in the male.Cp in D and V views (Fig. 8I, J) slightly more slender than in the male.
Soft parts (Figs 11C-F, 12A, B, D-F) largely as in the male, but with sexually dimorphic A2 and T1.
T1 (Fig. 12C) with basal part as in the male.Endopod a broad palp, with two short and one long distal setae.

Measurements
See Table 3.

Ecology
Together, both species have been found in 29 localities, in a total of 48 localities sampled in the alluvial valley of the Upper Paraná River, they occurred sympatrically in only 11 localities.
Candobrasilopsis rochai gen.nov.sp.nov.occurred in 17 localities in the alluvial valley.The pH ranged between 5.1 and 6.6, electrical conductivity between 13.2 and 66.9 μS cm -1 and dissolved oxygen between 1.2 and 8.6 mg L -1 .
Candobrasilopsis brasiliensis comb.nov.was found in 26 localities, with pH values ranging between 4.7 and 6.5, electrical conductivity between 23.6 and 114.9 μS cm -1 and dissolved oxygen between 0.6 and 13.3 mg L -1 .
These species were predominant in several types of substrates as sediment (named littoral in Table 1) and different species of fl oating macrophytes (Eichhornia crassipes, Pistia stratiotes, Hydrocotyle ranunculoides and Salvinia spp.) in different habitats (lakes, channels and rivers) (Table 1).

Remarks
As some small differences in hemipenis morphology between two different populations of this species were detected, we dissected a longer series of males from 3 populations and illustrated both hemipenes of each individual (Fig. 13).It is clear that indeed some variability exists, i.e. in the size of the proximodorsal expansion of the ls, as well as in the ventral expansion of the ms.Some of this variability might be a result of different positions of these organs between cover slip and glass slide.Therefore, we deem all of these populations to be conspecifi c.

Discussion
Candobrasilopsis versus Latinopsis Karanovic & Datry (2009) erected the genus Latinopsis, with the type species L. patagonica Karanovic & Datry, 2009 from Chile, based mainly on the fact that the length of the terminal segment of the Mdpalp is much shorter in this South American genus than in Candonopsis s.s.We agree that this is a signifi cant character that merits the distinction of a separate lineage within the Candonopsini.
Here, we describe a new genus with the same character, the short terminal segment on the mandibular palp, but which differs markedly from Latinopsis in a number of characters.Firstly, in the size and shape of the anterior calcifi ed inner lamella, which is narrow and of which the inner margin is evenly rounded, running parallel to the valve margin in Latinopsis patagonica, but which is ca.Karanovic & Datry, 2009) and an almost non-existant medial shield (Fig. 7A, C).The Candonopsini thus have at least 2 separate lineages within the Neotropics.

The position of Candonopsis anisitsi Daday, 1905
Karanovic & Datry (2009) also included several (older, and ill described) species into their new genus, including Candonopsis anisitsi Daday, 1905 from Paraguay.Of this latter species, they re-described type material and illustrated several of the limbs (not the valves, which were apparently missing in the type material).It is clear from this re-description that there are several differences between L. patagonica and C. anisitsi, for example (1) in the type of hemipenis, which has a 'Candona' -like appearance with lobes a and b in Latinopsis patagonica, but has the real 'Candonopsis' -type with triangular lateral shield (ls) and reduced medial shield (ms) in Candonopsis anisitsi (see above); (2) the morphology of the prehensile palps (almost symmetrical in Latinopsis patagonica and with distinct asymmetry in C. anisitsi and (3) in the size, shape and position of the seta 'b' on the endopod of the T1 (seta b large and stout and placed distinctly away from seta d in Latinopsis and Candobrasilopsis gen.nov.; small and positioned closely to seta d in C. anisitsi).There also appear to be differences in other aspects of the chaetotaxy between L. patagonica and C. anisitsi, but these are more diffi cult to interpret.For example, the rest of the chaetotaxy of the mandibular palp appears to be different between both species.
We agree that both species belong to related lineages within Candonopsini, and differ from Candonopsis s.s., but do not necessarily belong in the same genus.
New material of this species needs to be re-examined to determine the exact shape and position of seta b on T1 and of the shape and size of the anterior calcifi ed inner lamella (and of the inner margin) in this species.The other species transferred to Latinopsis by Karanovic & Datry (2009), namely Candona columbiensis Mehes, 1914 and Candonopsis falclandica Vavra, 1898, need to be re-examined in detail to see in which genus they belong.

Taxonomy of the Candonopsini
The taxonomic identity of the Candonopsini relied fi rst and foremost on the absence of the proximal seta of the caudal ramus.This feature is still the fi rst delimiting factor to distinguish between 'real' candonids on the one hand and candonopsines on the other hand.There are at present three genera with a welldeveloped caudal ramus (i.e. a strong ramus, with 2 well-developed claws) in which the proximal seta is missing: Candonopsis Vavra, 1891, Latinopsis Karanovic & Datry, 2009 and Candobrasilopsis gen.nov.These genera most likely belong to the same phyletic clade and can thus be united in a tribe, the Candonopsini.However, meanwhile several species with further reductions in the chaetotaxy of the caudal ramus have been described within Candonopsis s.s.(e.g. C. westaustraliensis Karanovic & Marmonier, 2002), while Marococandona Marmonier et al., 2005 comprises one species with fully developed caudal ramus (M.danielopoli) and one species in which the caudal ramus consists of only a ramus and one apical claw (M.nicolae).Moreover, several other genera with strongly reduced caudal rami have been lodged in the Candonopsini by Karanovic & Datry (2009) and Karanovic (2012): Abcandonopsis Karanovic, 2004 (here raised to generic rank), Cubacandona Broodbakker, 1983, Caribecandona Broodbakker, 1983, Marococandona Marmonier et al., 2005and Pioneercandonopsis Karanovic, 2005.
We have issues with this taxonomic situation, as it is almost certain that not all of these species and genera effectively belong to the same phyletic lineage.A reduction in size and chaetotaxy of the cypridoid caudal ramus has occurred many times in different lineages and is in fact one of the most common examples of parallel evolution (homeomorphy) in non-marine Ostracoda (see also McKenzie 1982).
The polyphyletic nature of the Candonopsini as defi ned by Karanovic (2012) is further demonstrated by the fact that the different genera have several other characters in which they differ from each other: "Carapace shape various (sic) (reniform, elongated, trapezoidal) (…), A1 7-segmented (…) or the number of segments reduced.Male sexual bristles on A2 present (…) or absent."(Karanovic 2012: 258).Other differences occur in hemipenis morphology.
A revision of the Candonopsini is urgently needed so that the different lineages which are presently grouped within it, can be recognised and can be properly classifi ed.

name sample Data S°S' S" W°W' W" Loc. type Subsystem substrate type WT EC pH DO C. rochai C. brasiliensis
comb.nov.were collected.Detailed occurrences are indicated in Table 1.Locality 13 (samples PAR193 and PAR195) is the type locality of C. rochai gen.nov.sp.nov.

" W°W' W" Loc. type Subsystem substrate type WT EC pH DO C. rochai C. brasiliensis
Number 13 refers to the type locality of C. rochai gen.nov.
3 times broader inCandobrasilopsis and which has a sinuous inner margin in both valves, not parallel to the anterior valve margin.In fact, the anterior calcifi ed inner lamella in Latinopsis species have a juvenile appearance, Danielopol 1978)y (2009: inKaranovic & Datry (2009:fi gs 1A, 3A) are correct, one would suspect a heterochronic valve development in this genus.Secondly, the hemipenis of Latinopsis patagonica is not at all of the type that is typical of 'Candonopsis' species: it has two distinct lobes (named a and b in Karanovic & Datry, loc.cit.) and as such is more of the 'Candona' s.l.-type (see extensive descriptions inDanielopol 1978).The hemipenis in 'Candonopsis' s.l., as in Candobrasilopsis gen.nov.and in C. anisitsi, has a large, triangular and pointed lateral shield (named lobe a in